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Article: Calpain-cleaved type 1 inositol 1,4,5-trisphosphate receptor (InsP3R1) has InsP3-independent gating and disrupts intracellular Ca2+ homeostasis

TitleCalpain-cleaved type 1 inositol 1,4,5-trisphosphate receptor (InsP3R1) has InsP3-independent gating and disrupts intracellular Ca2+ homeostasis
Authors
Issue Date2011
PublisherAmerican Society for Biochemistry and Molecular Biology, Inc. The Journal's web site is located at http://www.jbc.org/
Citation
Journal of Biological Chemistry, 2011, v. 286 n. 41, p. 35998-36010 How to Cite?
AbstractThe type 1 inositol 1,4,5-trisphosphate receptor (InsP(3)R1) is a ubiquitous intracellular Ca(2+) release channel that is vital to intracellular Ca(2+) signaling. InsP(3)R1 is a proteolytic target of calpain, which cleaves the channel to form a 95-kDa carboxyl-terminal fragment that includes the transmembrane domains, which contain the ion pore. However, the functional consequences of calpain proteolysis on channel behavior and Ca(2+) homeostasis are unknown. In the present study we have identified a unique calpain cleavage site in InsP(3)R1 and utilized a recombinant truncated form of the channel (capn-InsP(3)R1) corresponding to the stable, carboxyl-terminal fragment to examine the functional consequences of channel proteolysis. Single-channel recordings of capn-InsP(3)R1 revealed InsP(3)-independent gating and high open probability (P(o)) under optimal cytoplasmic Ca(2+) concentration ([Ca(2+)](i)) conditions. However, some [Ca(2+)](i) regulation of the cleaved channel remained, with a lower P(o) in suboptimal and inhibitory [Ca(2+)](i). Expression of capn-InsP(3)R1 in N2a cells reduced the Ca(2+) content of ionomycin-releasable intracellular stores and decreased endoplasmic reticulum Ca(2+) loading compared with control cells expressing full-length InsP(3)R1. Using a cleavage-specific antibody, we identified calpain-cleaved InsP(3)R1 in selectively vulnerable cerebellar Purkinje neurons after in vivo cardiac arrest. These findings indicate that calpain proteolysis of InsP(3)R1 generates a dysregulated channel that disrupts cellular Ca(2+) homeostasis. Furthermore, our results demonstrate that calpain cleaves InsP(3)R1 in a clinically relevant injury model, suggesting that Ca(2+) leak through the proteolyzed channel may act as a feed-forward mechanism to enhance cell death.
Persistent Identifierhttp://hdl.handle.net/10722/171787
ISSN
2015 Impact Factor: 4.258
2015 SCImago Journal Rankings: 3.151
PubMed Central ID
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorKopil, CMen_US
dc.contributor.authorVais, Hen_US
dc.contributor.authorCheung, KHen_US
dc.contributor.authorSiebert, APen_US
dc.contributor.authorMak, DODen_US
dc.contributor.authorFoskett, JKen_US
dc.contributor.authorNeumar, RWen_US
dc.date.accessioned2012-10-30T06:17:06Z-
dc.date.available2012-10-30T06:17:06Z-
dc.date.issued2011en_US
dc.identifier.citationJournal of Biological Chemistry, 2011, v. 286 n. 41, p. 35998-36010en_US
dc.identifier.issn0021-9258en_US
dc.identifier.urihttp://hdl.handle.net/10722/171787-
dc.description.abstractThe type 1 inositol 1,4,5-trisphosphate receptor (InsP(3)R1) is a ubiquitous intracellular Ca(2+) release channel that is vital to intracellular Ca(2+) signaling. InsP(3)R1 is a proteolytic target of calpain, which cleaves the channel to form a 95-kDa carboxyl-terminal fragment that includes the transmembrane domains, which contain the ion pore. However, the functional consequences of calpain proteolysis on channel behavior and Ca(2+) homeostasis are unknown. In the present study we have identified a unique calpain cleavage site in InsP(3)R1 and utilized a recombinant truncated form of the channel (capn-InsP(3)R1) corresponding to the stable, carboxyl-terminal fragment to examine the functional consequences of channel proteolysis. Single-channel recordings of capn-InsP(3)R1 revealed InsP(3)-independent gating and high open probability (P(o)) under optimal cytoplasmic Ca(2+) concentration ([Ca(2+)](i)) conditions. However, some [Ca(2+)](i) regulation of the cleaved channel remained, with a lower P(o) in suboptimal and inhibitory [Ca(2+)](i). Expression of capn-InsP(3)R1 in N2a cells reduced the Ca(2+) content of ionomycin-releasable intracellular stores and decreased endoplasmic reticulum Ca(2+) loading compared with control cells expressing full-length InsP(3)R1. Using a cleavage-specific antibody, we identified calpain-cleaved InsP(3)R1 in selectively vulnerable cerebellar Purkinje neurons after in vivo cardiac arrest. These findings indicate that calpain proteolysis of InsP(3)R1 generates a dysregulated channel that disrupts cellular Ca(2+) homeostasis. Furthermore, our results demonstrate that calpain cleaves InsP(3)R1 in a clinically relevant injury model, suggesting that Ca(2+) leak through the proteolyzed channel may act as a feed-forward mechanism to enhance cell death.en_US
dc.languageengen_US
dc.publisherAmerican Society for Biochemistry and Molecular Biology, Inc. The Journal's web site is located at http://www.jbc.org/en_US
dc.relation.ispartofJournal of Biological Chemistryen_US
dc.rightsJournal of Biological Chemistry. Copyright © American Society for Biochemistry and Molecular Biology, Inc.-
dc.subject.meshCalcium - metabolismen_US
dc.subject.meshCalcium Signaling - drug effectsen_US
dc.subject.meshCalpain - metabolism - pharmacologyen_US
dc.subject.meshInositol 1,4,5-Trisphosphate Receptors - metabolismen_US
dc.subject.meshIon Channel Gating - drug effectsen_US
dc.titleCalpain-cleaved type 1 inositol 1,4,5-trisphosphate receptor (InsP3R1) has InsP3-independent gating and disrupts intracellular Ca2+ homeostasisen_US
dc.typeArticleen_US
dc.identifier.emailCheung, KH: ckingho@hku.hken_US
dc.identifier.authorityCheung, KH=rp01463en_US
dc.description.naturelink_to_OA_fulltexten_US
dc.identifier.doi10.1074/jbc.M111.254177en_US
dc.identifier.pmid21859719-
dc.identifier.pmcidPMC3195633-
dc.identifier.scopuseid_2-s2.0-80053925001en_US
dc.identifier.hkuros200562-
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-80053925001&selection=ref&src=s&origin=recordpageen_US
dc.identifier.volume286en_US
dc.identifier.issue41en_US
dc.identifier.spage35998en_US
dc.identifier.epage36010en_US
dc.identifier.eissn1083-351X-
dc.identifier.isiWOS:000295927100073-
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridNeumar, RW=6603755941en_US
dc.identifier.scopusauthoridFoskett, JK=7005723620en_US
dc.identifier.scopusauthoridMak, DOD=35587181700en_US
dc.identifier.scopusauthoridSiebert, AP=24399993800en_US
dc.identifier.scopusauthoridCheung, KH=14007487800en_US
dc.identifier.scopusauthoridVais, H=6602154738en_US
dc.identifier.scopusauthoridKopil, CM=16480496900en_US

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